4-chloro-5-{2-[4-(6-fluoro-1,2-benz[d]isoxazole-3-yl)piperidine-1-yl]ethyl-amino}-2-methyl-3-(2H)pyridazinone of the Formula (I) and pharmaceutically acceptable salts thereof have been disclosed for the first time in published International Patent Application No. WO 03/010166 and in Hungarian Patent Application No. PO 103063.
It is known from the state of the art that 4-chloro-5-{2-[4-(6-fluoro-1,2-benz[d]isoxazole-3-yl)piperidine-1-yl]ethyl-amino}-2-methyl-3-(2H)pyridazinone of the Formula (I) is a drug candidate having a valuable neuroleptic effect useful in the treatment of psychoses, especially schizophrenia. The expression “neuroleptic effect” is understood according to the state of the art as the alleviating effect of the antipsychotic drug towards the embarrassment, delusions, hallucinations and psychomotoric excitation resulting from psychoses in patient suffering from such disorders.
In recent decades, several diseases have emerged in the of interest of medicinal research, which are associated with neuronal death, chronic neuronal decay, decline of mental capabilities or dementia resulting from the progress of aging.
Such disorders include multiple sclerosis, Creuzfeld-Jacob disease, Huntington's Disease, amyotrophic lateral sclerosis (ALS), Parkinson's Disease, stroke and neuronal death due to acute cerebral or spinal traumas or resulting from the exposure of toxic substances or as a result of ischemia. Characteristic symptoms of the above-mentioned disorders are a decrease of learning capability, loss of memory and in some cases, a decline in mental ability.
According to the state of the art, two types of memory are distinguished. The so-called “short-term memory” characterizes refers to the retention of information for a short interval of time spanning from some minutes to several hours. The expression “long-term memory” refers to the retention of information for the periods ranging from hours to years (Baddley and Warington, J. Verb. Learn. Verb. Behav. 9, 176-179); Wright et al., Science 229, 287-289).
The process of information transfer from short-term memory to long-term memory is referred to as consolidation.
The process of bringing back the information from either short-term or long-term memory is called retention.
Although total amnesia is relatively rare, the incidence of the disorders accompanied by confused memory or memory decline is increasing. Eighteen million people are suffering from Alzheimer's Disease worldwide and a significant increase in the number of patients suffering in this disease is expected in the upcoming years (Fletcher, MoI. Med. Today, 3/10 p. 429-434, 1997).